Methodology to estimate the transfer function of individual differential mobility analyzers

A method to estimate the nonideal features of the transfer function of indi vidual differential mobility analyzers (DMA) was developed and tested exper imentally. This was up to now an unsolved problem, which is important for t he precision in DMA measurements. The method involves three DMAs of unknown characteristics, which are used in three rounds of experiments with two DM As according to a fixed schedule. The width of the transfer functions of th e three DMAs is obtained in a single fitting procedure where one parameter is fitted to each DMA transfer function and the particle losses in each DMA are calculated in direct relation to that parameter and parameters known f rom the experiment. It was shown that the proposed method could solve the a pportioning problem and unambiguously estimate the transfer function width and the particle losses in each of the DMAs.